Green S M, Lambden P R, Caul E O, Ashley C R, Clarke I N
Department of Molecular Microbiology, University Medical School, Southampton General Hospital, UK.
Virus Res. 1995 Aug;37(3):271-83. doi: 10.1016/0168-1702(95)00041-n.
Studies of antigenic variation between small round-structured viruses (SRSVs) using immune electron microscopy have revealed 3 antigenic types currently circulating in the UK represented by the strains SRSV/Bri/93/UK, SRSV/Sot/91/UK and SRSV/Mel/89/UK. Mel/89/UK RNA was isolated from a 1989 school outbreak of gastroenteritis. The 3'-terminal 3435 nucleotides (excluding the poly(A) tail) were determined by RT-PCR and cDNA sequencing, completing our molecular characterization of antigenically diverse SRSVs. Coding regions for the calicivirus RNA polymerase and capsid protein were found together with a 3' open reading frame of unknown function. The polymerase region was most highly conserved between Mel/89/UK and the other two SRSVs while the 3' open reading frame exhibited extreme variation. Phylogenetic analysis of SRSV capsids showed that Mel/89/UK differed significantly from Bri/93/UK and Sot/91/UK (62 and 39% identity, respectively) and was distinct from 6 other non-UK SRSVs that had been previously characterized. This was consistent with the designation of Mel/89/UK as a novel antigenic variant. Comparison of the capsid amino acid sequences of the 3 UK strains together with the antigenically distinct SRSV/Nor/68/US revealed a hypervariable region that could be surface-exposed and contain the SRSV antigenic determinants.
利用免疫电子显微镜对小圆结构病毒（SRSV）之间的抗原变异进行的研究显示，目前在英国流行的有3种抗原类型，分别由毒株SRSV/Bri/93/UK、SRSV/Sot/91/UK和SRSV/Mel/89/UK代表。Mel/89/UK RNA是从1989年一次学校胃肠炎暴发中分离出来的。通过逆转录聚合酶链反应（RT-PCR）和cDNA测序确定了3'末端的3435个核苷酸（不包括聚腺苷酸尾），从而完成了我们对抗原性不同的SRSV的分子特征分析。发现了杯状病毒RNA聚合酶和衣壳蛋白的编码区以及一个功能未知的3'开放阅读框。Mel/89/UK与其他两种SRSV之间，聚合酶区域的保守性最高，而3'开放阅读框则表现出极大的变异。对SRSV衣壳的系统发育分析表明，Mel/89/UK与Bri/93/UK和Sot/91/UK有显著差异（分别为62%和39%的同源性），并且与之前已鉴定的其他6种非英国SRSV不同。这与将Mel/89/UK指定为一种新型抗原变异体是一致的。对3种英国毒株以及抗原性不同的SRSV/Nor/68/US的衣壳氨基酸序列进行比较，发现了一个高变区，该区域可能位于表面并包含SRSV抗原决定簇。
